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Date: Fri, 13 Jan 2012 14:09:57 -0600
From: Mark Tinguely <tinguely@sgi.com>
MIME-Version: 1.0
Subject: Re: [PATCH] repair: avoid ABBA deadlocks on prefetched buffers
References: <20111115210953.GA6670@infradead.org>
In-Reply-To: <20111115210953.GA6670@infradead.org>
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To: Christoph Hellwig <hch@infradead.org>
Cc: xfs@oss.sgi.com

On 01/-10/63 13:59, Christoph Hellwig wrote:
> Both the prefetch threads and actual repair processing threads can have
> multiple buffers at a time locked, but they do no use a common locker
> order, which can lead to ABBA deadlocks while trying to lock the buffers.
>
> Switch the prefetch code to do a trylock and skip buffers that have
> already been locked to avoid this deadlock.
>
> Reported-by: Arkadiusz Mi??kiewicz<arekm@maven.pl>
> Signed-off-by: Christoph Hellwig<hch@lst.de>
>

Part of a series of fixes. Needed for "
[PATCH 06/12] repair: use recursive buffer locking" patch.

Reviewed-by: Mark Tinguely <tinguely@sgi.com>

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